Work

Selective Solid Phase Extraction Using a Mixed‐Mode Cation Exchange Cartridge Facilitates the Mass Spectrometry Analysis on Dissolved Organic Nitrogen

Year: 2025

Type: article

Abstract: RATIONALE: Dissolved organic nitrogen (DON) is a crucial component in environment, which acts as the largest reservoir of nitrogen and plays a significant role in the nitrogen cycling, pollutant transport, and substrate utilization among various environmental systems. DON exhibits a relatively low concentration in environment, which presents a great challenge for DON detection, and an efficient separation and enrichment lab protocol is required to fully understand its structural and compositional characteristics. However, there is no standard method to extract DON from complex environmental samples efficiently. METHODS: The DON was extracted utilizing solid-phase extraction (SPE), with a one-step elution by the Bond Elut PPL cartridge and the Waters HLB cartridge, and a three-step elution by the Waters MCX cartridge. UV-Vis, fluorescence, mass spectrometry (MS), and gas chromatography-nitrogen chemiluminescence detector (GC-NCD) techniques were utilized to investigate and compare the characteristics of DON from the three different SPE strategies. RESULTS: Combined the fluorescence and MS results, it is found that the stepwise extraction using the MCX cartridge exhibits the best recovery of DON for both standard and environmental samples, and its performance is less affected by the chemical interferences such as surfactants during MS analysis. Furthermore, the MCX fraction exhibits the highest number of DON molecular formulas with a low O/C ratio and a high H/C ratio in environmental samples, and such a fraction also shows an enrichment of nitrosamine-type substances. CONCLUSIONS: This work establishes an efficient MCX-SPE protocol to extract and analyze DON, which can be applied to environmental samples straightforward. The presented work provides a theoretical support for the analysis of DON, which facilitates a comprehensive understanding of the chemical composition and environmental effect of nitrogen-containing substances.

Source: Rapid Communications in Mass Spectrometry

DOI: 10.1002/rcm.10037

Authors: Yuanyuan Dong, Wenrui Yao, Yulin Qi, Yufu Han, Chao Ma, Dietrich A. Volmer

Institutions: Tianjin University, Humboldt-Universität zu Berlin

Language: English

Topic: Analytical chemistry methods development

Subfield: Analytical Chemistry

Field: Chemistry

Domain: Physical Sciences

SDG: Clean water and sanitation

Open Access status: bronze

Funders: National Natural Science Foundation of China, China University of Petroleum, Beijing, State Key Laboratory of Heavy Oil Processing